Question

A cart of weight 10N is pulled 1.2 m up a ramp by an applied force of magnitude 5.0 N (parallel to the ramp), raising the cart 0.50 m above its initial level. Calculate the percentage efficiency of the work?

• A. 83.33%
• B. 85%
• C. 84.5%
• D. 86.33%

Answer 1

The correct option is A

83.33%

Weight of the cart = 10N
Vertical height = 0.5 m

Energy output = Potential energy
$=m\times g\times h$
$=10\times 0.5=5J$

Energy input = Work done to move the cart
$=Force\times displacement$
$=5\times 1.2=6J$
$\text{Percentage efficiency}$ $=\frac{Energyoutput}{Energyinput}$ = $\frac{5}{6}$ $\times 100$
$\text{= 83.33\%}$